Handle split selection when animation is disabled

* Consolidate setState() and setStateWithAnimation()
to be handled in the same manner
* If no animation, we run the created
PendingAnimation right away

Fixes: 209935590
Test: Tested w/ and w/o animation
Change-Id: I1d6fdba21761b6721e6bd52234016178547cd437

quickstep/src/com/android/quickstep/views/RecentsView.java

@@ -3994,7 +3994,7 @@ public abstract class RecentsView<ACTIVITY_TYPE extends StatefulActivity<STATE_T
     }
 
     /** TODO(b/181707736) More gracefully handle exiting split selection state */
-    private void resetFromSplitSelectionState() {
+    protected void resetFromSplitSelectionState() {
         if (mSplitHiddenTaskViewIndex == -1) {
             return;
         }